Hot metal extru-bending machine

ABSTRACT

This invention relates to the extru-bending machine that can bend product by extruding two or more hot metal billets with the machine which consists of an extrusion die holder equipped with conical dies, container holder heating the two or more-holed container with conical plug, two or more extrusion stems, hydraulic power system unit, relative velocity control unit, and support frame structure.  
     It is characterized that, when two or more hot metal billets are welded together inside a conical die cavity and extruded to one product at the die exit, the extru-bending machine can bend the extruded part simultaneously during extruding with the gradient of extrusion velocities on the dies exit owing to the relative moving velocity of two or more extrusion stems.  
     And it is possible to manufacture curved metal rods or tubes by the extru-bending machine without defects such as wrinkling and folding on the surface, distortion in the section, and thickness change in the wall.

TECHNICAL FIELD

[0001] This invention relates to the extru-bending machine that can bend the product by extruding two or more hot metal billets with the machine which consists of a extrusion die holder equipped with conical dies, a container holder heating the two or more-holed container with conical plug, two or more extrusion stems, an hydraulic power system unit, a relative velocity control unit, and support frame structure.

[0002] It is characterized that the extru-bending machine can bend products simultaneously while extruding with the gradient of the extrusion velocity at the die exit, owing to the difference of relative moving velocity of two or more extrusion stems, when two or more hot metal billets are welded together inside the conical extrusion die cavity and extruded to one product at the die exit.

BACKGROUND ARTS

[0003] When metal products are extruded by conventional extrusion machines, it is known that distorted bending may happen owing to the shape of the extruded section and the position of the die hole. Accordingly, such distorted bending has been regarded as a defect and these have been concern about preventing such defects. But, if the bending could be controlled during the extruding process by controlling the velocity gradient at the die exit, the extrusion machines can not only prevent distorted bending but also can take the place of the function of bending machines which can bend products with an arbitrary section. Because conventional extrusion machines have one hole in the container and cannot make uniform gradients in the moving velocity of the billet in the container, it is difficult to make and control a uniform velocity gradient at the die exit for bending. So, it is necessary to invent an extru-bending machine which has such a structure and function that can create and change the uniform velocity gradient at the die exit for the control of the curvature and the direction of bending.

DISCLOSURE OF INVENTION

[0004] The extru-bending machine consists of an extrusion die holder equipped with conical dies, a heated container holder, a two or more-holed container with conical plug, two or more extrusion stems moving at different velocities, an hydraulic power system unit pushing the extrusion stems, a relative velocity control unit, and the support frame structure.

[0005] Because the different velocities of two or more extrusion stems of the extru-bending machine can make a difference in the moving velocity of two or more billets inserted in the holes of the two or more-holed container. Accordingly, when two or more hot metal billets are coming at different velocity from the holes of the two or more-holed container, they are welded inside the conical extrusion die cavity and are extruded to one product at the die exit, and then bending should happen owing to the difference of the relative velocity of the extrusion stems.

[0006] Then, the bending curvature can be controlled by the difference of relative velocity of two or more extrusion stems. For example, when the velocity of one extrusion stem is constant, if the other symmetric extrusion stem should move fast or slowly, it can change the curvature or the direction of bending.

[0007] If the curvature of bending could be controlled in order not to bend while extruding by equalizing the velocity of variable velocity stem and the velocity of constant velocity stems, it is possible to get such an effect that can bend straight extruded metal tubes or rods by a conventional rotational bending machine. And it is possible to get such results that the extru-bending machine can bend extruded products without such defects as distortion of section, thinning of thickness, and wrinkling and folding on surface that can happen easily when they should be bended by conventional rotational bending machines.

[0008] On the other hand, the extru-bending machine can also control the bending curvature by adjusting the difference of relative size of the holes in the two or more-holed container. For example, although there is no difference in the relative velocity of extrusion stems, the machine can extrude and bend curved product with constant bending curvature by differing the size of holes in relation to each other.

[0009] The extru-bending machine is characterized by the arrangement of hydraulic cylinders in order to control the relative velocity of extrusion stems, in these way: by the number of extrusion stems, by the structure of the ram-crossheads, and by the structure of the two or more-holed container that are different from those of conventional extrusion machines.

BRIEF DESCRIPTION OF DRAWINGS

[0010] The nature and mode of operation of preferred embodiments of the present invention will now be more fully described in the following detailed description, taken with the accompanying drawings wherein:

[0011]FIG. 1 is a perspective overall view of the hot metal extru-bending machine of the present invention;

[0012]FIG. 2 is a cross-sectional view of the flow of hot metal in extru-bending process for the curved metal rod;

[0013]FIG. 3 is a cross-sectional view of the flow of hot metal in extru-bending process for the curved metal tube;

[0014]FIG. 4 is a perspective view of a constant velocity ram-crosshead and constant velocity stems;

[0015]FIG. 5 is a perspective view of a variable velocity ram-crosshead and a variable velocity stem;

[0016]FIG. 6 is a perspective view of a heated container holder equipped with a two or more-holed container and a die holder;

[0017]FIG. 7 is a view of examples of products of curved metal rods or tubes that can be manufactured by the present invention.

EXPLANATION OF THE SYMBOL AT THE INDICATED POINT IN THE DRAWINGS

[0018]1: constant velocity stem 2: variable velocity stem 3: two or more-holed container 4: conical dies 5: conical plug 6: right side billet 7: left side billet A: constant velocity hydraulic cylinder B: constant velocity ram-crosshead C: variable velocity hydraulic cylinder D: variable velocity ram-crosshead E: heated container holder F: extrusion die holder G: support frame structure H: relative velocity control unit I: hydraulic power system unit 100: curved metal rod 200: curved metal tube

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] For more details of the present invention, exemplary embodiments of extru-bending process using four extrusion stems and four-holed container are illustrated in the figures with detailed description as followings;

[0020] The extru-bending machine consists of constant velocity hydraulic cylinders (A), a constant velocity ram-crosshead (B), a variable velocity hydraulic cylinder (C), a variable velocity ram-crosshead (D), a heated container holder (E), an extrusion die holder (F), the support frame structure (G), a relative velocity control unit (H), an hydraulic power system unit (I) in FIG. 1 and constant velocity stems (1), a variable velocity stem (2), a two or more-holed container (3), conical dies (4) in FIG. 2 and conical plug (5) in FIG. 3.

[0021] The extru-bending principle of the present invention is explained as follows with attached drawings;

[0022] In FIG. 4, when the constant velocity ram-crosshead (B) which is connected to the ram of the upper and lower constant velocity hydraulic cylinders (A) moves in constant velocity, the constant velocity stems (1) connected to the constant velocity ram-crosshead (B) are moved in constant velocity. Because the constant velocity stems (1) consists of three extrusion stems of upper, lower and right sides except for one variable velocity stem (2) among the four extrusion stems, they are inserted in the three holes of upper, lower and right sides in the two or more-holed container (3) when they are moved by the constant velocity hydraulic cylinders (A).

[0023] In FIG. 5, when the variable velocity ram-crosshead (D) which connects to the ram of the variable velocity hydraulic cylinder (C) is moved in variable velocity by the relative velocity control unit (H), one variable velocity stem (2) which is connected to variable velocity ram-crosshead (D) can be moved slowly or fast in variable velocity independently from the constant velocity stems (1) and it can be slid through the sliding hole of the constant velocity ram-crosshead (B),

[0024]FIG. 2 is an example of the extru-bending process of curved metal rod. If the variable velocity stem (2) is moved more slowly than the constant velocity stem (1), because the left side billet (7) velocity by the variable velocity stem (2) is moved more slowly than the velocity of the right side billet (6), the extru-bending machine can extrude and bend in the direction of left side during the process of combining and welding the four billets inside conical die (4) cavity. And then, because there is no difference in the velocity of the upper and lower extrusion stem, the bending happens only in the direction of the left side without bending in the direction of the upper or lower side. Bending curvature and bending direction can also be controlled by the difference of the relative velocity of the variable velocity stem (2) and the constant velocity stem (1).

[0025]FIG. 3 is an example of the extru-bending process of curved metal tube. If the variable velocity stem (2) is moved more slowly than the constant velocity stem (1), because the velocity of the left side billet (7) is moved more slowly than the velocity of the right side billet (6), the extru-bending machine can extrude and bend in the direction of the left side during the process of combining and welding the four billets inside conical dies. And, because there is no difference in the velocity of the upper and lower extrusion stems, the bending happens only in the direction of left side without bending in the direction of the upper or lower side.

[0026] In contrast, if the variable velocity stem (2) is moved faster than the constant velocity stem (1), because the velocity of the left side billet (7) moves faster than the velocity of the right side billet (6), the extru-bending machine can extrude and bend in the direction of the right side. And, if the variable velocity stem (2) is moved at the same velocity as the constant velocity stem (1), the extru-bending machine can extrude only straight extruded metal rods or tubes without bending as in conventional extrusion processes.

[0027] In this way, when straight product is being extruded, if the velocity of the variable velocity stem (2) is instantaneously fast or slow, and again, if it is the same velocity as the constant velocity stem (1), the extru-bending machine can extrude curved products as in FIG. 7 and can get such effects as being able to bend by conventional rotational bending machines. And in FIG. 7, the extru-bending machine can bend extruded products with complicated sections which are difficult to bend, and products having various curvatures.

[0028] The velocity control of the variable velocity stem (2) in order to control bending directions and curvatures can be done by using the relative velocity control unit (H) connected to the variable velocity hydraulic cylinder (C) driven by the hydraulic power system unit (I) with flow control valves controlled by computer.

[0029] Although the above embodiments are illustrated as desirable examples of the case of the extru-bending process using four hot metal billets, with four extrusion stems, and with a four-holed container, the fulfillment with the technically applicable range of the present invention can be made in any other case of the extru-bending process using two or more hot metal billets, with two or more extrusion stems, and with a two or more-holed container.

INDUSTRIAL APPLICABILITY

[0030] The present extru-bending machine can be used for bending the curved rods or tubes while extruding in order to eliminate such defects as thinning or thickening in the walls of the product, distortion of the section, and wrinkling or folding on the surface after bending process.

[0031] This present invention can be classified as a complex metal forming machine with a new structure and function which is different from the concept of conventional extrusion machines, and it can contribute to increase productivity by combining the extrusion process and the bending process. And, because the machine can bend products with complicated non-symmetric sections which are difficult to bend, there can be many applicable fields for industry. 

1. The extru-bending machine which consists of extrusion die holder (F) equipped with conical dies (4) in which one is able to insert conical plug (5) for the purpose of bending product while extruding owing to the difference of moving velocity of each billet when two or more hot metal billets are welded inside the conical die (4) cavity and are extruded to one product at the die exit after coming from the holes of the two or more-holed container (3).
 2. The extru-bending machine which consists of a heated container holder (E) equipped with the two or more-holed container (3) connected with conical plug (5) for the purpose of bending product at the die exit while extruding owing to the difference of moving velocity of two or more extrusion stems inserted in the holes of the two or more-holed container or owing to the difference of relative size of two or more holes.
 3. The extru-bending machine which consists of constant velocity stems (1) that can be moved in constant velocity and equipped at the constant velocity ram-crosshead (B) connected to constant velocity hydraulic cylinders (A); and which consists of variable velocity stems (2) that can be moved in different velocities and equipped at the variable velocity ram-crosshead (D) connected to variable velocity hydraulic cylinder (C) for the purpose of bending product at the die exit while extruding owing to the difference of relative velocity of two or more extrusion stems inserted in the holes of the two or more-holed container (3).
 4. The extru-bending machine which consists of hydraulic power system unit (I) equipped with flow control valves controlled by computer in order that the variable velocity ram-crosshead (D) connected to variable velocity hydraulic cylinder (C) should move differently from the constant velocity ram-crosshead (B) connected to constant velocity hydraulic cylinders (A) for the purpose of bending product at the die exit during the extrusion process.
 5. The extru-bending machine which consists of a relative velocity control unit (H) being able to control the bending direction and curvature while extruding by making the variable velocity stem (2) move slower or faster than the constant velocity stems (1) for the purpose of bending product at the die exit during the extrusion process.
 6. The extru-bending machine which is operated in the method by which the bending direction and curvature can be controlled by the difference of relative moving velocity of the variable velocity stem (2) and the constant velocity stems (1); by the difference of relative size of two or more holes in the two or more-holed container (3); by the eccentricity of center of exit and entrance sections of conical dies (4) and conical plug (5) for the purpose of bending product at the die exit during the extrusion process.
 7. The extru-bending machine which manufactures curved metal rods (100) or curved metal tubes (200) with an arbitrary section in various curvatures by controlling the difference of relative velocity of the variable velocity stem (2) according to the curved geometry of product inputted in the computer of the relative velocity control unit (H). 